Summaries of health policy coverage from major news organizations

Study: Mammograms Read by Computers Less Effective

Radiologists using computer-aided detection software for mammograms are more likely to interpret a benign growth as potentially cancerous than "human reviewers using their eyes and experience," and CAD systems do not help detect more cancers, according to a study published in Thursday's New England Journal of Medicine, the Los Angeles Times reports (Gellene, Los Angeles Times, 4/5).

CAD systems use complex algorithms to identify "suspicious" areas of a mammogram for a radiologist to review, according to the Wall Street Journal (Armstrong, Wall Street Journal, 4/5). The systems, which cost $50,000 to $175,000, were approved by FDA in 1998 and are sold by several companies, the New York Times reports.

Medicare gives providers extra $20 more for administering mammograms that use CAD, and the systems are used in 30% of mammography centers, according to the National Cancer Institute.

For the study, Joshua Fenton of the University of California-Davis and colleagues examined 429,345 mammograms performed at 43 medical centers from 1998 to 2002. During the study period, seven of the centers began using CAD (Kolata, New York Times, 4/5).

According to the study, CAD systems correctly identified which women had tumors and which did not 87.2% of the time, compared with 90.2% for standard screening. CAD systems also led to 31% more women being called back for more tests and 20% more biopsies, the study found.

The researchers estimate that for every additional woman who was diagnosed with breast cancer using CAD, 156 had unnecessary additional tests and 14 had unnecessary biopsies. The researchers said that CAD systems did find more of a type cancer known as ductal carcinoma in situ, which tends to be less dangerous, the Washington Post reports.

Wide use of the systems also would raise annual cost of mammography by 18%, or about $550 million, the study found.

Comments, Reaction

Fenton said the "goal of [CAD] systems was to make mammography better." He added, "Our study suggests that, if anything, they appear to be doing more harm than good" (Stein, Washington Post, 4/5).

Suzanne Fletcher, an emerita professor of ambulatory care and prevention at Harvard Medical School, said, "With mammography, we have multiple studies showing what happens to mortality rates if you get [the screening] versus if you don't. With [CAD systems] we don't" (New York Times, 4/5).

Some radiologists expressed caution about the study -- funded by NCI and the American Cancer Society -- saying that the technology continues to evolve and that larger studies are needed to confirm and expand upon the results. According to some radiologists, the performance of CAD also could be improved with better training of physicians using the technology.

"We have a tool that helps us find smaller abnormalities and earlier indications of the disease," Rob Cascella -- president of Hologic, the maker of the best-selling CAD system, which was used in the study -- said (Wall Street Journal, 4/5).

Editorial

Ferris Hall -- a radiologist at Beth Israel Deaconess Medical Center in Boston who wrote an accompanying NEJMeditorial -- said some mistakes might have been a result of inexperience with CAD because it takes radiologists several years to learn the technology.

Nonetheless, the study is a setback for the technology, Hall said, adding, "This will have a major impact on radiology" (Los Angeles Times, 4/5).

Broadcast Coverage

CBS' "Evening News" on Wednesday reported on the study. The segment includes comments from Katherine Lee of the Cleveland Clinic Breast Center and study co-author Joanne Elmore of the University of Washington (LaPook, "Evening News," CBS, 4/5). Video of the segment is available online.

NPR's "All Things Considered" on Wednesday also reported on the study. The segment includes comments from Elmore and Hall (Knox, "All Things Considered," NPR, 4/5).